Radio signaling apparatus



Feb. 2 1926. 1,571,371

G. H. CLARK RADIO SIGNALING APPARATUS Filed March 17, 1921 Patented Feb.v 2, 1926.

UNITED STATES 1,511,371 PATENT OFFICE.

GEORGE E. CLARK, OI BROOKLYN, NEW YORK, ASSIGNOR TO RADIO CORPORATION OF AMERICA, A. CORPORATION OF DELAWARE.

RADIO SIGNALING APPARATUS.

Application filed larch 17, 1921. Serial No. 162,895.

To all whom it may concern:

Be it known that I;'i.GEoRcn H. CLARK, a citizen of the Uni-ted States, and a resident of Brooklyn, New York, have invented certain new and useful Improvements in Radio Signaling Apparatus, of which the following is a specification accompanied by drawings.

The present invention relates to improvements in radio signaling with. continuous waves. As is well known, high frequency continuous waves or oscillations are incapable of audible reception without special means utilized either' lat the transmission station or at the receiving station.

In case that the waves are modulated at an audible rate at the transmitting station no special means are necessary at the receiving station for detection and any receiving set equipped for detection of damped waves will detect the modulated continuous waves. In modulating the wave at the transmission station it is usual to superimpose an E. M. F. of low frequency on the main E. M. F. in the antenna or changethe constants in the antenna at an audible;.rate in order to produce the modulation.

Instead of thus changing the constants of the antenna or adding currents from another source I periodically absorb at an audible rate portions of the signal waves so that the same do not-f. get in the antenna. Thus the signal current in the antenna is in efl'ect interrupted at an audible rate by the absorption in a non-radiating circuit of portions of the generated oscillations.

WVhile my invention is applicable to various types of high frequency continuous wave generating systems, it is described in connection with an arc converter system which has the so-called nondadiating absorption circuit for producing the signal. Normally in this part cular embodiment of the invention the current is periodically absorbed in this absorption circuit at an audible rate and a telegraph key working in conjunction with the modulating or periodical y absorbing means, sends substantially all of the oscillations into the absorption circuit in one position and in the other sends the interrupted wave into the antenna. In this way the dots and dashes of the signal are in efiect interrupted at an audible rate and the signals can beindicated by receiving stations even though they are .not

equipped with high frequency continuous wave receiving apparatus. 7

One object of my invention is therefore to alternately send the oscillating current into the antenna and the absorption circuit, such alternation taking place at an audible rate.

A second object is to provide means for sending all of the oscillatory current into the absorption circuit at desired intervals so as to produce the signaling characteristics such as by dots and dashes.

Further objects of the invention will appear in the following description in which the single figure of the drawing represents an arc converter system embodying my in vention. j 1

In the drawings, 1 is an are fed by a generator 2 and having a field coil 3 to provide the field for influencing the arc in the well known way. The antenna 4 is connected to the upper electrode through adjustable loading coil 5 and the lower electrode is connected to the ground at 6. For absorbing the generated oscillations an absorption circuit is connected to the are which consists of an inductance 7, capacity 8 and resistance 9. In shunt to resistance 9 I have arranged an interrupting device consisting of a disc 10 having alternate conducting and non-conducting portions and on this disc bears-a brush 11 which is joined to one side of the resistance 9. A brush 12 engaging a disc 13 on shaft 14 is connected to the other side of the resistance. When the brush 11 is on one of the conducting sections of disc 10 resistance 9 is short circuited and when the brush rests on the insulating sections the short circuit around the resistance is removed. Telegraph key 15 is connected through wire 16 to one side of resistance 9 and contact 17, which the key is adapted to engage in one position, is connected to the other side of the resistance. When the key is in the position shown in the drawing the resistance 9 and interrupting device are short circuited and the values of the inductance 7 and capacity 8 are such that substantially all of the oscillations produced by the arc generator are absorbed in this absorption circuit so that there is no radiation. The interruption device continues to rotate but on account of the resistance being short circuited by the key it produces no effect.

To signal, the operator will press down the short circuit around resistance Conequal amplitude at, code.. .signal frequency, and sorbi ngl' p orltions thereof at an audio frequency.

tinuous W ai d un h olren oscillations would be sent into the antenna asjloj i g "as the k depressed were it not for tlieinterrupt'iiig graph key is held down to make a act or dash, the interrupting{device 10 is: co-ntin ually establishing and removing a short c1r- .device, but during the time, that -theirtele frequency continuous oscillations which con- SlSt S 111'plfiOdLlQlngQOSClllfli/lOIlS by the succuit around res stance 9) so that, :tho' I dot 2 O1"- dash current in theai tenn a a group, ,of; continuous waves. When-the brush is on theiconducting segnientei disc momentarily; short circuited and I a por imlu of the dot or dash is absorbed in the absoripetion circuit. I Immediately; afterwardsavheii the brusli -engages thevinsulating section this 7 7 short circult 1s ren ioyed;and; another. portion of the dot-.Qr dash is-asent into theiantennau In this Way signaling is producedihy means.

of. unvarying W&'V lengths and; a- :portionuof ically absorbed at-anaudihlerate.

While I have described z-iny, inventionin theyg'roups offwajves of the signal are, period? I connection With an arc converter systein it;

is not limited tosuch an arra'ngemeg'nt as signal Wavesican beabsorhed: in anon-radix. ating circuit atiregular iiitenvals;-regardless of the type. of oscillat on,.ggenerator-"em-i adapted to shunt said resistance periodical constant amplitude, diverting portions there'fl of to an HbSOI'bHIg'JIIBQJISifltU'ELDQZLHdIO fre quency during signaling periods: and divert- 3 ing all? thereof to I-the absorbingimeans during non-sig-na-ling periods; i

v2. 1133: method; of signaling; with high ireqi'iency contlnuous oscillations which consists n producing groups of oscillations of fll ie method ofsignaling with} high cessive and alternate interaction of a radiating circuit and a noii radiating circuit With a: generator. at audio frequency, v during signaling .periods, and suspending the succes sion during non-signaling periods.

:4. zlnia radiotzsignalingi systen'i a generator ofgcontinuous oscillations, an antenna circuit, an absol'loing circuit, means foreleglivering oscillations alternately to said an: tenna c1rcu1t andiito said absorbingcircuit at an audio'i'requency during signaling periods,v and 111821118 for confining said oscillationstosaidabsorbingcircuit I during non-signaling 1 5. In a. radio signaling system, a generator of continuous oscillations, an antenna circuit,

and absorbing circuit adapted toabsorb ie'iiergyitherefroni, means :for rendering-said ab sorbing c1 IClllt' alternately ineffective: and etfectiveat an audible frequency, and meansifor.

rendering; it: steadily, efiective at a code; sige naling .-frequency.-;- i i ,;6.T:In rairadio; signaling ;syst.em, an", are

oscillation z enerato'r, an antenna connected sistance ellenients a commutator "device ly' atk-an-audioi frequency rate, 'and'a "key also adapted eto -sliunt: .sai dresistance at a signalingratem 1 l GEoR Gni e OLARIC Y i thereto, an absorption;- circuit also connected. theneto and comprising impedance and vrec-Y. 

